Printers are known which comprise an ink jet head section wherein an ink cartridge is used to supply ink to the ink jet head section. In such printers, when the ink cartridge becomes empty, it can be replaced with a full one. An ink cartridge loading mechanism comprises an ink supply needle placed at a fixed position and an ink cartridge is placed in such a manner that the ink supply needle is inserted into an ink supply port of the ink cartridge.
An ink cartridge of the structure disclosed in Japanese Laid-Open Patent No. Hei 5-16378 by the present applicant is known. This ink cartridge consists of a flexible ink bag in which ink is sealed, an ink supply port leading from the ink bag, and a hard plastic case containing the ink bag. Generally, the plastic case is shaped like a flat rectangular parallelopiped and the ink supply port leading from the ink bag is exposed to the front end face of the plastic case. Therefore, the ink cartridge is placed in such a manner that the ink supply needle of the printer is inserted into the ink supply port of the ink cartridge.
To insert the ink supply needle into the ink supply port in an appropriate fashion and attach the ink supply needle, the ink cartridge needs to be moved in a sliding fashion in the direction of the needle. Generally, an ink cartridge loading part is disposed in the front or rear portion of the printer and the ink cartridge is slidable horizontally from the front or rear side, whereby it can be attached or detached.
However, in such a loading mechanism for sliding the ink cartridge in one direction from the front or rear side of the printer, it is necessary to open widely the portion of the printer having the loading mechanism. Thus, the following problems are involved:
First, in a printer adapted to replace an ink cartridge therein from the rear, the printer cannot be installed near or on a wall. In such a case, even if the footprint of the printer itself is small, a large installation space for the printer is nonetheless required.
On the other hand, in a printer adapted to replace an ink cartridge therein from the front, accessories and other equipment related to the printer cannot be placed on the front face of the printer. For example, with a printer used for POS application, input units such as a tablet, a keyboard, and a scanner and a display unit for displaying data, etc., entered through the input units may be placed in front of the printer. Thus, the printer adapted to replace an ink cartridge therein from the front requires that the accessories should be moved away when an ink cartridge is replaced; such an arrangement is not preferred from the viewpoint of ease of use.